Gene Therapy Restores Sight in Second Eye, Research Finds

Kim LaCapria

Three patients who participated in a gene therapy study have “reported a dramatic improvement in vision after having gene therapy in both eyes,” the BBC has reported.

All three patients in the study were born with Leber’s Congenital Amaurosis (LCA), an autosomal recessive disorder that involves “mistakes” in ten genes- causing retinal defects that often present with nystagmus, inhibited pupillary responses, and possible severe vision loss or blindness. Trials in gene therapy to reverse the effects of the disorder are currently being carried out in several countries, but only a few of the patients participating have, according to the BBC, “received the treatment to boost a faulty gene underlying an inherited form of blindness.”

Back in 2008, researchers in the US reported improvement in one eye in 12 subjects treated with gene therapy. An engineered virus with the gene RPE65 was injected into one of both eyes, and patients reported that some vision was recovered. Three of the 12 were re-treated in the second eye, and researchers observed the additional treatment “improved their sight even more.” Two of the three were able to dodge obstacles, and all three experienced enhanced vision in low light.

Lead researcher Dr. Jean Bennett told the BBC:

“We’ve shown that it is possible to safely treat both eyes of people with this particular form of retinal deficiency using a gene-based treatment and further we’ve demonstrated that the brain understands what the retina is seeing.”

One of the three patients treated, Tami Morehouse, told the BBC:

“Life is so much easier at a level that most people take for granted. Any amount of vision that you can get when you have almost nothing is incredibly valuable.”

More research is planned to apply the gene therapy findings to other, similar conditions.